Archive for the 'AR-15s' Category

We have previously discussed the Marine Corps battle with the Army and Congress over fielding a different ammunition than the Army, who spent a wad of money on an “environmentally friendly” lead-free cartridge, the M855A1.

Currently, the Marine Corps is trending towards the MK 318, which appears to be a far superior round, and it comes in right at 2900 FPS out of the M4 barrel, higher for longer barrels.  The claim is that it behaves better at longer distances and retains its ability to penetrate.

This trend towards heavier rounds has been going on for some time now, and 62 grains isn’t the top weight for the 5.56mm bullet.  One reader sends information about Sierra 77 grain, and tells me that the 1:9 twist is just fine with this ammunition.  Of course, one gives up something to get something.  In the case of heavier bullets, you give up muzzle velocity.

This velocity detriment may seem small.  TFB likes the Sierra 77 grain, and informs us that its muzzle velocity comes in somewhere between 2500 FPS and 2600 FPS.  But your choice of ammunition will depend upon your target, its distance, any interstitial shielding, potential body armor, etc.

You may do better with M193 than with either the MK 318 or the Sierra 77 grain.  Sometimes the smaller rounds with the higher muzzle velocity are what’s needed to penetrate any armor.  Do you not believe me?  Consider what we learned with the FN 5.7 and its test against bulletproof glass, which only the .454 Casull could penetrate.  The open tip 5.7 round at 22 grains penetrated the glass due to high muzzle velocity, whereas the heavier 5.7 round did not.

Do you need more evidence?  Very well.  Consider that AR500.com sells hard plates it calls Level III, and those plates are rated to stop M855 (steel core) but cannot stop M193.  They have to move up to what they call Level III+ to perform effectively against the M193 due to its higher muzzle velocity compared to the M855.  There’s nothing wrong with having a safe full of M193.

Tom McHale has a very good article at Ammoland on AR-15 rifle barrel lengths and whether it matters.

Remember that you have two competing effects on muzzle velocity.  First, it’s advisable to get as much work out of expanding gases as feasible in order to increase muzzle velocity.  Second, there is friction in the barrel, which is a detriment to the work being done by the expanding gases.

So there is a turnover point on the curve of barrel length versus muzzle velocity, where you no longer gain muzzle velocity with increased barrel length.  So McHale performed some testing of barrel lengths, and this is what he came up with.

The difference between the 16″ and 18″ barrel is greater than the difference between the 18″ and 20″ barrel.  But barrel lengths greater than 18″ doesn’t buy you much.  McHale also has some data on the .300 Blackout round that looks interesting.

The one thing he didn’t give us is the effects of 14.5″ barrels (as with the M4), or pistol length barrels (e.g., 10″ barrels).  I would like to see some test data on that, and unless persuaded otherwise I have to believe that the SpecOps trend to use shorter and shorter barrels lengths along with suppressors is adversely effecting muzzle velocity.

Ammoland:

RTH Firearms today released its first semiautomatic production rifle chambered in 6.5x47mm Lapua or 6.5mm Creedmoor precision cartridges.

These rifles achieve amazing precision, hitting below sub-MOA at 100 yards with the ability to reach 1,400 yards with very little felt recoil.

Here is a picture of it.

Sweet rifle, yes?  Here is the web site, and here is the URL for the gun.  Now get ready for the sticker shock.  Are you ready?

$6,899.99.

We covered precision shooting and semi-automatic mid-range caliber rifles before, and I noted that the guns were in that price range as well, most of them special order guns.  They’re not shelf guns, they’re not even mid-range priced.  These aren’t even highly priced, as you can get designated marksman rifles that will shoot < 1 MOA for much less than that.

I’m sure this gun is nice, but folks, what good is it, realistically, to have a gun that shoots < 1 MOA as compared to a gun that shoots 1 MOA, unless you’re a professional precision shooter or a professional sniper in the military?  And not only that, what good is it to have a gun that can shoot better than you can?

I admitted to my failures several weekends ago, failures that had to do with not checking my dope before I started shooting, and failing eyesight forcing me to consider a higher power scope.  Perhaps with perfect eyesight (uncorrected), years of experience, and your livelihood depending upon accuracy, it makes sense to worry over this sort of thing.

I suppose that they are targeting the very people I said would be interested in this gun, rather than the typical man who has trouble affording even much less than that, even for a really nice AR.  It would be nice to have a mid-range caliber AR that shoots well and doesn’t tear the gun up (like I hear about AR-10s and the .308), but until manufacturers are able to pull the price down by a wide margin, this isn’t going to happen for the common man.  They won’t be making many of these guns.

In the mean time, it’s easy enough to take my really nice ARs and slap a .300 Blackout upper receiver on it (which takes 10 seconds) and have a really nice mid-caliber AR that shoots 1 MOA or slightly less, which is as good as I can shoot anyway.

I found a lot of what Travis has to say in this video very helpful and useful.  I think you will too.

The main conclusion is that this is a decent budget AR.  He put it through what looked like a fairly comprehensive torture test, although I don’t know how many AR-15s or what brands he has put through the test.

Vickers Tactical.  Nice video.  Courtesy of reddit/firearms.  Eugene Stoner rules.

Outdoor Hub:

There’s no question – the AR-15 doesn’t look like your daddy’s deer rifle. Of course, the Winchester Model 94 lever-action rifle your granddad used doesn’t look anything like his father’s Hawken, either.

However, we see progress all around us. The smartphone is nothing like the rotary phones I grew up with, and if my grandpa stepped in my pickup truck, he’d think it was a spaceship.

The American hunter is experiencing this same thrust into the 21st century. While it might not have the lure, feel and warmth of walnut and blued steel, performance matters over nostalgia. I’m not suggesting you trade in your old .30-30 on an AR, or regulate your bolt rifle to the closet for all eternity. What I hope you will do is consider the many factors that make the AR-15, and its bigger brother the AR-10, ideal for deer hunting.

We’re living in a brave new world and the AR is the hunting rifle of the new millennium – and here’s why.

He goes on to describe a number of things my readers already know about the AR that make it a good choice, including man-machine interface, modularity and adjustability, reliability, etc.  Then there is this.

There does exist more powerful options for those who demand it. Nine of the 41 states permitting centerfire rifles for deer hunting prohibit the use of the .223 Remington. If you hunt in one of those states, the 6.8 SPC or .300 Blackout are an option, as is the new .25-45 Sharps, which duplicates the performance of the old .250 Savage. If you want to stretch your range or just think you need more power, you can step up to an AR-10 and choose a cartridge like the .243 Winchester, 6.5 Creedmoor, .308 Winchester, and in some cases even magnum cartridges.

The semi-automatic AR-15s that shoot anything but the 5.56/.223 or 300 Blackout are non-existent to my knowledge, and the AR-10s that shoot anything else can be very pricey (except for .308).  Or in other words, designer cartridge black guns are very expensive – even the AR style bolt action guns.

But I do like the idea of the 300 Blackout, where I can swap out an upper receiver quickly and easily and have a larger round, slightly slower muzzle velocity, but better long range ballistics than the 5.56/.223 (while I would also assert than the 5.56/.223 is ideal for many situations that don’t suit the 300 Blackout).

So in summary I would say to the old time hunters with puzzled looks at the kids bringing out the new fangled black guns, you need to welcome them and perhaps even learn something.  They are carrying on a proud tradition.  To the Fudds who refuse to accept it, I would say get over it.  Your opinions don’t matter.

But here is a word of caution for the AR hunters.  Know you rifle, know your round, and know your limitations.  Make ethical shots.  Only make ethical shots.

The call it the Saint.  For the moment I’ll hitch a ride on The Firearm Blog, and then criticize some of their commenters.

Patrick R reviews the gun for readers, and generally has nice things to say about it.  It seems to fit into the low to medium cost AR-15, and it’s always good to have competition.  It makes everybody better.

Patrick discusses what he perceives to be the accuracy of the gun, but as you read this, remember my claim.  A few shots cannot reveal the true accuracy.  I reject claims of 1 MOA, or 0.75 MOA from any gun manufacturer or shooter unless the sample size is large.  Any gun manufacturer or shooter, not just SA.  The placement of shots for any gun should be able to be represented by a standard distribution – excluding variations caused by the shooter – with a standard deviation that is small enough to be less than the mean (because a standard deviation larger than the mean only makes physical sense and is only allowed when the mean can go negative, which cannot happen in this case).  Three shots, or five shots, means that the sample size is too small to accomplish this and meet the central limit theorem.

It has a keymod rail, and the commenters savage this rail system, and Patrick even says there are better options.  Well, I don’t know about that.  It depends.  It’s weak and tends to break, say the commenters.  Well, I have some exposure to a RRA competition rifle, 18″ SS fluted barrel, with a slotted rail that is much lighter than others (right, I understand that we aren’t reviewing the RRA competition rifle).  Most readers have a black gun with a quad picatinny rail.  Me too, excepting that awful boating accident where all of my guns, including this 3-gun competition gun with the light slotted rail, went to the bottom of the lake.  I cried a river of tears over that accident.

It’s forend heavy because of that quad rail, isn’t it?  Just say yes.  You know it is.  Don’t lie to yourself.  My former Marine son Daniel’s experience in Fallujah put him at odds with heavy equipment, including heavy forend guns.  He dislikes the quad rail for that reason.  He told me “The first thing I would do with that gun is remove the rails and replace it with something light weight.”  I wonder how many of TFB commenters who think the lighter rail system sucks had to raise it and conduct room clearing operations for 24 straight hours in Fallujah while they were dehydrated in 120 degree heat, with nothing to eat, people shooting at you, and stomach cramps from drinking the local water?  That’s what I thought.

Look, I’m not saying that you have to have a quad rail.  I’m not saying you have to have a lighter rail competition gun or a keymod rail.  I’m not saying you have to have or do anything at all.  I’m saying that you find the tool that works best for you for the purpose you intend, learn it, take care of it, and appreciate it.  Rarely should you listen to the counsel of folks who make categorical statements.  A heavy quad rail is okay if you don’t intend to conduct long term operations of any sort with it, and it can handle all sorts of attachments that you might want.  A lighter rail has the advantage of not over-rotating the gun when attempting target acquisition moving laterally (not over-rotating is the main reason behind the thumb-over-bore grip that has become so popular).  Each tool has its own purposes.  I’ve actually seen complaints by people when they used their butt stock to beat up something and it broke.  Folks, your gun isn’t a hammer.

The gun doesn’t have a floated barrel, and I wonder how much that affects accuracy (it does some by adding a fundamental node [or an eigenvalue] in the vibration, we just don’t know how much).  But there is one feature that will be problematic for Springfield Armory.  The top of the rail is polymer, and melts with heat generated from long term operation of the gun.  This absolutely must be fixed or that’s a fatal flaw.

Ammoland:

At our Urban Rifle (Carbine) Courses, most students bring ARs, as you might imagine, but we see dozens of other types/brands, some of which I was heretofore only marginally aware, so many are the companies, worldwide, making small arms today.

But my colleagues and I, Dave Spaulding, Tom Givens, Mas Ayoob, James Yeager, Frank Sharpe, Manny Kapelsohn, Jeff Chudwin, Clint Smith, Freddie Blish, et al continue to see repeated handling errors, which during a genuine encounter for which we train, will be fatal!

Some students pick it up right away. Others fumble repeatedly. Most “get it” eventually, training themselves to avoid common AR rifle handling errors!

We instruct students to grab the 30-round magazine (which most use) with the support-side hand as they would a pop-can and smartly insert it into the magazine well. Then, strike the bottom of the newly-inserted magazine. Then, grab it and tug downward, trying to pull it back out.

When the magazine stays in place, it’s good to go.

Conversely, when it comes right back out again, it was never locked in place correctly!

I’m not trying to cast doubt on experts and their recommendations for gun handling, but perhaps this has to do with poor quality guns and poor quality magazines.  But I’ve put thousands upon thousands of rounds through ARs, and I’ve never once had a magazine fail to seat, and I don’t routinely strike the magazine on the bottom.

What about your experience with the AR?

At this reddit/guns post?

By mounting the light directly on the barrel, he’s adding a secondary harmonic, possibly exacerbating a primary node or creating an anti-node, or creating nodes completely out of sync with other nodes, and fundamentally changing the way the barrel vibrates.  Someone needs to tell him to remove the light and figure out another way.